Vaccination is one of the most cost-effective approaches in preventive medicine. Over the past 3 decades, new techniques in recombinant DNA and biotechnology have offered unprecedented opportunities for developing new vaccines. Many training opportunities exist to prepare individuals for research in immunology, molecular genetics, infectious diseases, and other specific aspects of vaccine development, but few training programs offer broad exposure to both laboratory and clinical trial aspects of vaccinology as a cohesive discipline. For the past 37 years, the Center for Vaccine Development of the University of Maryland School of Medicine has been involved in all aspects of vaccine development, from basic laboratory studies involving genetic construction of recombinant vaccines to Phase 1 through Phase 4 clinical trials. We propose to continue a formal training program in which individuals with M.D. or Ph.D. (or equivalent) degrees can be prepared specifically for careers in vaccinology, either to pursue basic vaccine development research or to conduct investigative clinical trials and translational research. Two new trainees will join the training program in each of the five years and training for each trainee will ensue fr 3 (sometimes 4) years. Support only for years 1 and 2 is requested in this proposal; support for the 3rd and possible 4th years will come from fellowships, research grants, or other sources. The Training Program in Vaccinology offers to all trainees a broad exposure to both the laboratory and clinical trial phases of vaccinology. Beyond this broad exposure, the program has two tracks to provide each trainee with intensive experience in either the laboratory aspects or the clinical phases of vaccinology, depending upon which track they choose. The Laboratory Track allows the training of basic scientists and physician-scientists in vaccine development laboratory research, particularly in the use of recombinant DNA technology to prepare new vaccine candidates and the use of modern immunological techniques to study the human humoral and cellular immune response to vaccines. The Clinical Track trains clinicians (internists or pediatricians) in trial design, protocol development, regulatory and ethical clearances, performance of clinical trials, data analysis and clinical translational research. The ultimate goal of this training program is to provide a well-trained cadre of individuals who can fully exploit the unprecedented opportunities now available in vaccine development.